Marijuana use may worsen the prognosis for young adults with psychosis. How can mental health providers help them quit?

Twelve years after Washington and Colorado became the first states to legalize recreational marijuana, it’s safe to say weed is here to stay. Nearly 30% of adults in Washington report having used cannabis in the past month, and a majority of Americans believe that marijuana products are safe.

When it comes to the safety of long-term marijuana use in the general population, the jury is still out. But there are some groups for whom cannabis poses a serious health risk.

Among the most vulnerable are young adults with psychosis, who tend to use cannabis excessively and whose symptoms can be exacerbated by long-term marijuana use. A team of researchers from the University of Washington is focusing on this particular group.

To effectively treat these patients’ symptoms and improve long-term outcomes, it is critical that healthcare providers help young adults stop using marijuana as soon as possible after their first psychotic episode. But that is proving difficult. Current best practices are not always effective for young adults with psychosis, who use cannabis for different reasons than their peers and who may experience different effects.

This poses a difficult problem for mental health providers: how can they best understand why their patients are using cannabis and what is the best way to help them quit?

UW researchers Denise Walker and Ryan Petros, of the School of Social Work, and Maria Monroe-DeVita, associate professor in the UW School of Medicine’s department of psychiatry and behavioral sciences, studied motivations within this group and subsequently developed a new treatment method.

A pilot study of 12 people showed the method to be effective, though final results have not yet been published. UW News sat down with the research team to discuss their intervention and why it’s so important to help young people in this group reduce their use.

Cannabis use is increasing across the board, but the numbers are alarmingly high among young adults with psychosis: you cite statistics that estimate that 60%–80% have used cannabis at some point in their lives. What makes someone experiencing psychosis so much more likely to use cannabis?

Walker: Many people probably used cannabis before their psychosis symptoms began, because there is strong research evidence that cannabis increases the risk of developing psychosis-related disorders. For those who do develop a psychosis-related disorder such as schizophrenia, continued cannabis use hinders the recovery process and makes outcomes worse.

There is still much to learn about the cause and effect of these relationships, but cannabis appears to have a unique relationship with psychosis.

Petros: Also, there is some evidence that suggests that people with schizophrenia get bored more easily than people without schizophrenia. In general, many people use cannabis because they like it and the high that comes with it.

It may be that people with schizophrenia spectrum disorders are more likely to use cannabis to have fun and feel good, because they are more likely to get bored and less pleasure from daily activities. But the fact is, we don’t really know.

Another reason people use cannabis is generally because it facilitates social interactions or provides a shared activity in social settings. Because people with schizophrenia spectrum disorders have smaller social networks and fewer social commitments, it may be that they use cannabis to facilitate enhanced social interactions, but again, we need more research to know for sure.

Central to all this research is the different health risks of cannabis use for people with and without psychosis or other mental health conditions. What are these differences and why is cannabis use among young adults with psychosis so concerning?

Petros: For people with psychosis, cannabis use is associated with higher rates of treatment dropout and reduced adherence. It leads to increased symptoms of psychosis and higher rates of psychiatric rehospitalization. In the long term, cannabis use increases the risk of poor psychosocial outcomes and reduced global functioning.

Walker: In essence, continued cannabis use makes it much harder for young adults with psychosis to benefit from treatment, make progress in their recovery, and ultimately live the lives they want.

Petros: Another major concern is that not only is cannabis use increasing, but people are becoming more tolerant of cannabis. Cannabis recently overtook alcohol as the drug most commonly used daily in the United States.

While some people can use cannabis without any problems, it is recommended that others stop using it altogether. However, over time, people have come to believe that cannabis use has health benefits, and they are less likely to see the risks of using it.

This can create particularly challenging circumstances in helping someone with psychosis to understand the real risks that cannabis use poses to their health and well-being, and to help them make the choice to reduce or stop using.

Walker: I agree. Perceptions around cannabis are often polarized: it is often seen as either “good” or “bad,” when in reality it falls somewhere in the middle. There may be benefits for some in using cannabis and real risks of harm for others. These mixed messages, or at least the lack of recognition of harm, contribute to ongoing hardship for those experiencing psychosis and their families.

What methods are currently recommended to help people reduce their cannabis use, and why might they not be as effective for young adults with psychosis?

Walker: The gold standard treatment involves a combination of motivational enhancement therapy (MET), cognitive behavioral therapy (CBT), and contingency management. Contingency management is often not available in the community, and studies show that MET plus CBT perform almost as well.

Because it is normal for motivation to wax and wane in someone considering changing their cannabis use, MET addresses the issue of motivation early on. CBT teaches skills to avoid drug use, cope with social situations and negative moods, and solve problems without using cannabis. Family therapy is another option with strong support.

The big problem is that we don’t know if these treatments are effective for young adults with psychosis. MET is the most studied intervention in cannabis treatment, alone and in combination; however, it has not been tested in young adults with psychosis. With a few tweaks, we believe it could outperform the general population, and we have begun testing it in young adults with psychosis.

Your team has developed an intervention for young adults with psychosis that incorporates MET. Can you describe what that intervention looks like and why it might be more effective for this population?

Walker: MET is a person-centered, nonjudgmental approach that facilitates honest, candid conversation about cannabis use. The techniques are designed to uncover individuals’ personal reasons for making a change and increase their motivation to do so.

Individual feedback is created based on a client’s responses to an assessment of their cannabis use and related experiences. The feedback summarizes information about their cannabis use patterns, how their cannabis use compares to others, and what the risk factors are for developing cannabis dependence.

It also provides clients with the opportunity to reflect on their personal goals and how their cannabis use helps or hinders them in achieving those goals.

When we asked young adults with psychosis what they wanted from a cannabis intervention, they were clear that they wanted an individualized and nonjudgmental approach. They also said they wanted accurate, science-based information about the relationship between cannabis and psychosis. MET ticks those boxes.

With a few adjustments, this is an ideal format for providing objective information while at the same time inviting the young adult to talk about it and reflect on what the information means to him or her personally.

Currently, healthcare providers are giving patients the message that cannabis is harmful to people with psychosis, which is a good start. But most healthcare providers don’t feel confident enough to discuss why cannabis is harmful and what the research has found.

I feel like patients often take that message and defend against it with their own personal experiences of what they like about cannabis. MET offers an invitation to receive and discuss objective evidence, to consider their own experiences of how cannabis affects their symptoms and what they want for their future, and to do so in a supportive environment that allows for a variety of perspectives on their use.

You ran a pilot program to understand how the new intervention works. What did you learn in that pilot study?

Walker: We’ve adapted the MET intervention to provide personalized feedback on the interaction between cannabis and psychosis, and we’ve added some graphics and ideas on ways to reduce those risks, beyond abstinence.

Twelve young adults with psychosis who regularly used cannabis enrolled in the study and were offered the intervention. Most participants were not interested in changing their cannabis use at the beginning of the study, and several chose to reduce their cannabis use at the end.

Overall, feedback was very positive. Participants overwhelmingly said they would recommend the intervention and remember the psychosis-specific parts of the conversation. They appreciated the data that was included and the opportunity to discuss what it meant to them.

They also said they enjoyed talking about how cannabis fits into their larger life and goals for the future. Overall, the feedback suggests that this intervention is promising and should be studied in a larger study.

Monroe-DeVita: My long-term goal is to offer this novel intervention as an adjunct to or integrated into the evidence-based package of services known to work best for people experiencing a first episode of psychosis.